Why system throws "kernel: Debug: sleeping function called from invalid context at kernel/workqueue.c:264" message ?

Issue

• server reboots with following kernel traces:

kernel: Debug: sleeping function called from invalid context at kernel/workqueue.c:264
kernel: in_atomic():1[expected: 0], irqs_disabled():0
kernel: 
kernel: Call Trace:<IRQ> <ffffffff80132c7d>{__might_sleep+173} <ffffffff8011e884>{flat_send_IPI_mask+0} 
kernel:        <ffffffff80147a93>{flush_workqueue+26} <ffffffff8011e884>{flat_send_IPI_mask+0} 
kernel:        <ffffffff8019b098>{__put_ioctx+65} <ffffffff8019b7e8>{aio_complete+442} 
kernel:        <ffffffff80199b1f>{finished_one_bio+161} <ffffffff80199d12>{dio_bio_complete+154} 
kernel:        <ffffffff80199d43>{dio_bio_end_aio+28} <ffffffffa0232680>{:emcp:PowerPlatformTopIodone+112} 
kernel:        <ffffffffa02326d2>{:emcp:PowerTopIodone+34} <ffffffffa023284c>{:emcp:PowerProcessTopIodonePirps+76} 
kernel:        <ffffffffa0232c65>{:emcp:PowerBottomIodoneNew+693} 
kernel:        <ffffffff8024ff52>{__end_that_request_first+238} <ffffffffa0006d99>{:scsi_mod:scsi_end_request+40} 
kernel:        <ffffffffa00070ae>{:scsi_mod:scsi_io_completion+497}